JP2009084096A - Apparatus and method for cutting glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for cutting glass in which a crack formed in a glass plate can be controlled to achieve good cutting results. <P>SOLUTION: The apparatus comprises a placing board on which a glass plate is placed, a placing board driving means which moves the placing board in the uniaxial direction, a laser beam oscillation part which oscillates a laser beam to the glass plate, and a sensor which detects the crack of the glass plate formed by the laser beam. The placing board driving means determines the movement speed in the uniaxial direction of the placing board depending on the degree of extension of the crack detected by the sensor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a glass cutting device and method, and more particularly to a glass cutting device and method capable of stably cutting a glass plate by controlling the extension of cracks formed in the glass plate.

  When manufacturing a flat display panel such as a liquid crystal display panel and a plasma display panel, a display element and a circuit are formed on a single glass substrate and divided along a predetermined dividing line to thereby form a single glass. A plurality of panels are taken out from the substrate. As this panel, a pair of glass substrates on which a metal such as an electrode is formed is bonded with an adhesive or the like, and the laser cutting apparatus is not limited to such a bonded glass but other brittle materials, etc. It is also used for cutting.

FIG. 5 shows a glass cutting method using a conventional CO ₂ laser. A cut is formed in the cutting start end portion 51 of the glass substrate 50 using a wheel cutter. Then, while irradiating the surface of the glass substrate 50 with an infrared laser such as the CO ₂ laser 60 that does not transmit the glass, the CO ₂ laser is scanned relative to the glass substrate 50, and the vicinity of the rear of the laser irradiation unit is scanned. Quench with a coolant 65 such as pure water. Thereby, a thermal stress is generated on the surface of the glass substrate 50 to form the scribe line 55, and then the glass substrate 50 is bent by applying a breaking force to the glass substrate 50, whereby the glass substrate 50 is scribed. Cleave along.

  In Patent Document 1, the surface of the brittle nonmetallic material is superheated to a temperature lower than the softening point of the brittle nonmetallic material by irradiation of a radiation beam, and the region is located at a position a predetermined distance behind the overheated target region. There is disclosed a method for dividing a brittle non-metallic material by supplying a coolant and defining a relative moving speed between the radiation beam and the brittle non-metallic material main body based on the size of the beam spot and the predetermined distance.

Japanese Patent No. 3027768

  However, each glass plate has a difference in the degree of internal stress, a variation in physical properties, and the like, and even when the glass plate is cut under the same conditions, a difference in the result is produced. Therefore, in order to realize stable cutting of the glass plate, it is necessary to form a good crack by controlling the extension of the crack due to laser irradiation. As described above, when controlling the extension of cracks using a coolant such as water, it takes time to treat the water, and it is arranged on the lower side when two glass plates are cut and stacked. There was a problem that the glass plate could not be cooled.

  The present invention has been made in view of such problems, and by directly measuring the elongation of cracks formed in the glass plate, the measurement result is reflected in the relative speed between the laser beam and the glass plate. An object of the present invention is to provide a glass cutting device and method capable of controlling cracks extending in a glass plate and forming good cracks.

  A glass cutting device according to the present invention includes a laser beam scanning unit that scans a laser beam oscillation unit that oscillates a laser beam and a laser beam irradiation unit from the laser oscillation unit along a predetermined cutting line of a glass plate to be cut. , A sensor for detecting a tip position of a crack generated in the glass plate by the irradiation of the laser beam, and a crack detected by the sensor for moving speed when the glass plate is moved relative to the irradiation unit. And a control unit for controlling the tip position to follow the appropriate position of the crack tip determined by the laser beam irradiation unit.

  The control unit may increase the relative movement speed between the glass plate and the irradiation unit to a predetermined value regardless of elongation of the crack at the start end of the crack.

  In addition, the control unit may prevent the tip position of the crack from overtaking the irradiation unit between an allowable upper limit value and an allowable lower limit value of a relative moving speed between the glass plate and the irradiation unit. It is characterized by controlling.

  In the glass cutting method according to the present invention, the glass plate is cut by irradiating the glass plate to be cut with a laser beam, and scanning the laser light irradiation portion along a predetermined cutting line. A step of detecting a tip position of a crack generated in the glass plate by irradiation of the laser light with a sensor, and a tip of the crack detected by the sensor when moving the glass plate relative to the irradiation unit; And a step of controlling the position so as to follow an appropriate position of the crack tip determined by the laser beam irradiation portion.

  In addition, the relative movement speed between the glass plate and the irradiating portion is increased to a predetermined value at the starting end portion of the crack regardless of the elongation of the crack.

  Further, it is controlled between the allowable upper limit value and the allowable lower limit value of the relative moving speed between the glass plate and the irradiation unit so that the tip position of the crack does not pass the irradiation unit. And

  As described above, according to the present invention, it is possible to control a crack that extends without using a coolant, so that there is an effect that it does not take time to process the coolant.

  In addition, since the extension of the crack can be directly measured and reflected in the moving speed of the laser, the formation of a more stable crack can be achieved, and the cutting speed of the glass plate can be improved.

  The best mode for carrying out the glass cutting apparatus and method according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view showing a glass cutting device and method according to an embodiment of the present invention. The glass cutting device 70 includes a mounting plate 20, a mounting plate motor 25, a ball screw 26, a laser emitting unit 30, and a sensor 40.

  The mounting plate 20 on which the glass plate 10 is mounted includes two nuts (not shown) below, and each nut is similarly connected to a ball screw 26 disposed below. One end of the ball screw 26 is connected to a mounting plate motor 25 that can rotate the ball screw 26 in an arbitrary direction. When the mounting plate motor 25 rotates arbitrarily, the mounting plate 20 can move in any one axial direction (left-right direction) along the arrow in the figure. In addition, the movement method of the mounting board 20 is not limited to the said method, It can select from a well-known technique.

  The laser emitting unit 30 is attached above the mounting plate 20 at a position facing the glass plate 10. The laser emitting unit 30 scans the laser irradiation position along a desired cutting line from the initial crack forming position 11 formed at the end of the glass plate 10 while emitting the laser beam 31 at a constant focal length. The scanning of the laser beam irradiation position 32 can be realized by rotating the mounting plate motor 25 and rotating the ball screw 26 connected to the mounting plate 20. In this embodiment, the case where the mounting plate 20 is moved in the direction of the arrow in the drawing (right direction) is shown.

  When the laser beam 31 is emitted from the laser emitting unit 30 to the glass plate 10, a relatively wide range is heated across a desired cutting line, and thermal stress is generated in the glass plate 10. That is, the glass plate 10 receives the laser beam 31 and absorbs it, and the irradiated portion generates heat. As a result, thermal stress is generated due to the difference in thermal expansion between the verification site and the site where the ambient temperature is low. Therefore, thermal stress is formed symmetrically on both sides of the cutting line, and tensile stress is generated. When this tensile stress exceeds the strength of the glass plate 10, a crack 12 starting from the initial crack is generated. And the crack 12 expand | extends when the laser verification position 32 scans a desired cutting line.

  By maintaining the tip position of the crack 12 extending to the glass plate 10 (hereinafter referred to as the crack tip position 13) at an appropriate position with respect to the laser verification position 32, the uniform crack 12 can be obtained as desired in the glass plate 10. It can be formed into a cutting line. Therefore, the extension of the crack is controlled so that the crack tip position 13 formed on the glass plate 10 follows the crack tip proper position 15. In order to control the elongation of the crack 12, the glass cutting device 70 according to the present invention has a sensor 40 that detects the crack tip position 13 and a moving speed of the mounting plate 20 based on information obtained from the sensor 40. A mounting plate motor 25 to be changed and a control unit 100 for controlling them are provided.

  The sensor 40 is disposed above the placement plate 20 at a position facing the glass plate 10. The sensor 40 is preferably fixedly attached to the laser emitting unit 30 in order to detect the crack tip position 13 and clarify the positional relationship with the laser light irradiation position 32. The sensor 40 can grasp the crack tip position 13 by photographing the glass plate 12 and performing image processing on the photographed image. In addition, the sensor 40 can be selected from those known in the art. For example, the crack tip position 13 may be grasped by sensing irregular reflection caused by the occurrence of a crack using a displacement sensor that emits a laser.

  The crack tip proper position 15 indicates the optimum crack tip position 13 with respect to the laser beam irradiation position 32 at a certain point in time when the glass cutting device 70 is in operation. The crack tip appropriate position 15 is determined empirically by the dimensions of the glass plate 10 to be cut and the characteristics of the laser beam 31 to be irradiated. FIG. 1 shows a case where the crack tip position 13 is located on the + side of the crack tip appropriate position 15 (when the crack 12 is slow to extend on the right side in the figure). As described above, when the crack tip position 13 does not reach the crack tip proper position 15, it is assumed that the crack tip position 13 is on the + side with respect to the crack tip proper position 15. On the contrary, when the crack tip position 13 is formed beyond the crack tip proper position 15 (when it is on the left side in the figure), the crack tip position 13 is on the negative side with respect to the crack tip proper position 15. To do.

  When the crack tip position 13 is separated from the crack proper position 15, a defect is caused in the formation of a good crack. For example, when the crack tip position 13 is far away to the + side, even if the laser beam 31 is irradiated, the crack 12 does not extend any further. On the other hand, if the crack tip position 13 is far away from the negative side, the crack tip position 13 may exceed the laser beam irradiation position 32 and extend the crack 12 in an unexpected direction. In order to form a good crack 12 without causing a problem in the extension of the crack 12, the control unit 100 controls each device.

  FIG. 2 shows a block diagram of a glass cutting machine according to the present invention. The control unit 100 issues a command to the motor driver 26 to drive the mounting plate motor 25 and also issues a command to the laser oscillator 35 to irradiate the glass plate 10 with laser light from the laser emitting unit 30. The tip position of the crack formed by the laser light irradiation is detected by the sensor 40, and the obtained information is sent to the control unit 100. The control unit 100 issues a command to the motor driver 26 based on this information, and drives the mounting plate motor 25 so that the tip position of the crack follows the appropriate position.

  The control unit 100 stores a processor (not shown), a ROM (Read Only Memory) that stores a program that defines a processing procedure by the processor, a program that is executed in response to an appropriate numerical input by a user, and necessary information. RAM (Random Access Memory). The control unit 100 issues an emission command to the laser emission unit 30 by a program stored in the ROM or an input from a user, and drives and controls the mounting plate motor 25 based on information obtained from the sensor 40. .

  FIG. 3 is a flowchart illustrating a crack control method for the glass cutting machine described in FIG. Hereinafter, the control method of the crack 12 is demonstrated using this flowchart. Note that the control of the crack 12 is performed by the control unit 100 unless otherwise specified.

  When starting to cut the glass plate 10, the mounting plate 20 is accelerated regardless of the crack tip position 13 (S111). And the moving speed of the mounting board 20 is raised to more than the set minimum speed (S112). Thus, by setting the upper limit speed in addition to the lower limit speed to the moving speed of the mounting plate 20 and limiting the range of the moving speed of the mounting plate 20, excessive movement of the mounting plate 20 is prevented. Thus, stable cutting work can be performed. The range of the moving speed is set in consideration of the physical properties and dimensions of the glass plate 10 to be cut, the characteristics of the laser beam 31 to be checked, and the like.

  When the moving speed of the mounting plate 20 exceeds the lower limit, the sensor 40 is started and it is checked whether the crack tip position 13 is at the proper position 15 (S113). At this time, if it is determined that the position is on the negative side of the appropriate position 15 (S114), if the moving speed of the mounting plate 20 is equal to or lower than the upper limit (S115), acceleration processing of the mounting plate 20 is performed (S116). . If it is determined that the crack tip position 13 is on the + side of the appropriate position 15 (S114), if the moving speed of the mounting plate 20 is equal to or higher than the lower limit (S117), the mounting plate 20 is decelerated. (S118). As described above, when the crack tip position 13 exceeds the proper position (when it is on the negative side), the mounting plate 20 is accelerated, and when it does not reach the proper position (when it is on the positive side). By performing the deceleration process of the mounting plate 20, the crack tip position 13 can follow the appropriate position 15.

  Here, when the crack tip position 13 is at an appropriate position in S113, or when the moving speed of the mounting plate 20 is the limit speed in S115 and S116, the current moving speed of the mounting plate 20 is maintained. .

  Below, control of the crack 12 by the control part 100 is demonstrated using FIG.

  FIG. 4 is a graph showing an outline of the crack control method of the glass cutting machine described in FIG. The upper graph in the figure shows the relationship between the mounting plate moving speed and time. The lower graph shows the relationship between the crack tip position and the time synchronized with the upper graph. Each Roman numeral written in the graph indicates a period indicated by an arrow during operation of the glass cutting machine 70. Hereinafter, the mounting plate moving speed commanded by the control unit 100 based on the crack tip position 13 detected by the sensor 40 will be described for each period. In the present embodiment, it is assumed that a certain amount of laser light 31 is emitted from the laser emitting unit 30 simultaneously with the operation of the glass cutting machine 70, and the laser output is not controlled.

  I period has shown the time of the cutting start of the glass plate 10 by the glass cutting machine 70. FIG. When the cutting of the glass plate 10 is started, the mounting plate 20 is accelerated to the set lower limit speed (graph white circle) regardless of the crack tip position 13 (denoted as a forced drive period in the graph). By doing so, the deadlock state of the program stored in the control unit 100 can be prevented.

  When the mounting plate moving speed is accelerated until it reaches the lower limit speed, the control unit 100 starts the sensor 40. Thereafter, the sensor 40 continues to measure the crack tip position 13 until the end of cutting. Since the crack tip position 13 (graph white circle) measured at the time of starting the sensor 40 is located on the negative side (see FIG. 1) of the appropriate position 15, the acceleration state of the mounting plate moving speed is maintained.

  Eventually, when the sensor 40 confirms that the crack tip position 13 has reached the proper position, the current movement speed of the mounting plate 20 is maintained (period II).

  When the sensor confirms that the crack tip position 13 maintained at the appropriate position 15 in the period II is located on the + side of the appropriate position 15, the mounting plate 20 is decelerated (period III). The amount of deceleration of the mounting plate moving speed is determined experimentally and experimentally in consideration of the material and dimensions of the glass plate to be cut, the characteristics of the irradiated laser beam, and the like. As described above, when the extension of the crack 12 does not reach the proper position 15, the control unit 100 decelerates the mounting plate 20 to return the crack tip position 13 to the proper position 15.

  When the sensor 40 confirms that the crack tip position 13 has moved from the + side to the − side across the appropriate position 15 by the deceleration operation of the mounting plate 20 performed in the period III, the control unit 100 mounts. The mounting plate 20 is accelerated (IV period). As described above, when the extension of the crack 12 exceeds the proper position 15, the control unit 100 accelerates the mounting plate 20 to return the crack tip position 13 to the proper position 15.

  When it is confirmed by the sensor 40 that the crack tip position 13 has moved from the negative side to the positive side across the appropriate position 15 by the acceleration operation of the mounting plate 20 performed during the IV period, the control unit 100 is loaded. The mounting plate 20 is decelerated (V period). At this time, even if the moving speed of the mounting plate 20 reaches a preset lower limit speed, if the crack tip position 13 does not return to the appropriate position 15, the lower limit speed is maintained.

  When it is confirmed by the sensor 40 that the crack tip position 13 has moved from the + side to the − side across the appropriate position 15 by the control operation of the mounting plate 20 performed in the V period, the control unit 100 mounts. The mounting plate 20 is accelerated (IV period). At this time, even if the moving speed of the mounting plate 20 reaches a preset upper limit speed, if the crack tip position 13 does not return to the appropriate position 15, the upper limit speed is maintained.

  Thus, if the glass cutting machine and method which concern on this embodiment are used, the moving speed of a glass plate can be changed according to the expansion | extension of the crack formed in a glass plate. Thereby, since the front-end | tip position of the extending crack can be maintained in the optimal position which can form a favorable crack, the stable cutting | disconnection of a glass plate is attained.

  In addition, the simple structure of detecting the tip of the extending crack with a sensor and controlling the motor that drives the mounting plate based on the information obtained from the sensor allows the crack to be formed faster, and the cutting speed is reduced. Improvements can be made.

The schematic diagram showing the glass cutting device and method concerning the embodiment of the present invention. The block diagram of the glass cutting machine which concerns on this invention. The flowchart explaining the control method of the crack which concerns on this invention. The graph which showed the outline | summary of the control method of the crack which concerns on this invention. Perspective view showing a method for cutting glass using a conventional CO ₂ laser.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Glass plate 11 Initial crack formation position 12 Crack 13 Crack tip position 15 (Crack tip) proper position 20 Mounting plate 25 Mounting plate motor 26 Motor driver 26 Ball screw 30 Laser emitting part 31 Laser beam 32 Laser beam irradiation position 35 Laser oscillator 40 sensor 70 glass cutting device 100 control unit

Claims (6)

  A laser beam oscillation unit that oscillates a laser beam, a laser beam scanning unit that scans a laser beam irradiation unit from the laser oscillation unit along a predetermined cutting line of a glass plate to be cut, and irradiation of the laser beam. A sensor for detecting a tip position of a crack generated in the glass plate, and a tip position of the crack detected by the sensor when moving the glass plate relative to the irradiation unit is the laser beam irradiation unit. And a control unit that controls to follow the appropriate position of the crack tip determined by the above.   The control unit increases a relative moving speed between the glass plate and the irradiation unit to a predetermined value regardless of elongation of the crack at a start end portion of the crack. The glass cutting device described in 1.   The control unit performs control so that the tip position of the crack does not pass the irradiation unit between an allowable upper limit value and an allowable lower limit value of a relative moving speed between the glass plate and the irradiation unit. The glass cutting device according to claim 1 or 2, characterized in that.   In the glass cutting method for cutting the glass plate by irradiating the glass plate to be cut with laser light and scanning the laser light irradiation portion along a predetermined cutting line, the glass plate is irradiated with the laser light. The step of detecting the tip position of the crack generated in the sensor by the sensor, and the tip position of the crack detected by the sensor by the sensor when the moving speed when the glass plate is moved relative to the irradiation unit is And a step of controlling to follow an appropriate position of the determined crack tip.   5. The glass cutting according to claim 4, wherein a relative moving speed between the glass plate and the irradiation unit is increased to a predetermined value at a starting end portion of the crack regardless of elongation of the crack. Method.   Control is performed so that the tip position of the crack does not overtake the irradiation unit between an allowable upper limit value and an allowable lower limit value of a relative moving speed between the glass plate and the irradiation unit. The glass cutting method according to claim 4 or 5.

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